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Development of nanomaterials for cultural heritage conservation: evaluation on the degradation state of antique coins by spectroscopic techniques

Oliveira, Maria Inês Baião Ramos de
Fonte: Universidade de Lisboa Publicador: Universidade de Lisboa
Tipo: Dissertação de Mestrado
Publicado em //2014 ENG
Relevância na Pesquisa
Tese de mestrado em Química (Química-Analítica), Universidade de Lisboa, Faculdade de Ciências, 2014; This work is presented in two complementary parts covering the two main fields on the study of cultural heritage. The first one is focussed on the analysis of a set of six dinheiros from the first Portuguese dynasty (13rd and 14th centuries). The coins were analyzed using μ-Energy Dispersive X-ray Fluorescence in order to evaluate their elemental composition, allowing to confirm in four of the coins a billon alloy (copper/silver) and in the remaining two a reduced content of silver. This fact is compatible with the social and economic Portuguese reality during D. Fernando I reign. The coins were further evaluated by means of X-ray Diffraction identifying natives copper and silver, as well as some of their degradation products, such as cuprite, tenorite, malachite, nantokite and atacamite and on the numisms with high silver content, chlorargyrite. By making use of Scanning Electron Microscopy/Energy Dispersive Spectroscopy the morphological analysis on the coins surface was performed evidencing the corroded surface and allowing to identify different morphologies corresponding to copper/copper oxides and silver/silver chloride phases. On the second part...